Dynamics of Binding of Lysozyme with Gold Nanoparticles: Corona Formation and its Correlation with a Naked-Eye-Based Colorimetric Approach

Abstract

The interaction between colloidal gold nanoparticles (AuNPs) and lysozyme (Lyz) has been studied through spectroscopic and microscopic measurements, molecular docking simulation and colorimetric measurements to investigate corona formation and the mechanism, affinity, number of sites and stoichiometry of binding. Molecular docking simulation endorses that, at physiological pH, the interaction between basic NH2 group of arginine and citrate ions is predominant than the interaction between citrate ions and the positive surface charge of the bare AuNPs that result in the desorption of citrate ions from Au surfaces and finally, electrostatic interaction between [Formula: see text] group of arginine and positive charge surface of AuNPs results in the adsorption of Lyz on Au surfaces. As observed from Benesi–Hildebrand and fluorescence analyses, the ground state complex formation between Lyz and AuNPs requires several minutes, which is approximately 11 min in the present work to attain stoichiometric ratio 1:1. CD spectra indicate insignificant or no conformational change in the secondary structure of Lyz in the presence of AuNPs. The time variation of LSPR peak position and peak height in the presence of Lyz have been studied extensively through spectroscopic and microscopic measurements. Detailed discussion on the probable time-specific roles of change in local dielectric constant, plasmon coupling and electrostatic interaction on these variations has been presented. Colorimetric change of the AuNPs-Lyz system with time has been analyzed by measuring the red, blue and green color fractions as well as its correlation with the process of corona formation and aggregation has been investigated to propose a novel naked eye colorimetric approach of studying these processes in AuNPs-Lyz system.

Interaction of Colloidal Gold Nanoparticles with Urine and Saliva Biofluids: An Exploratory Study

“…Because AuNRs display an opposite surface charge than AuNSs and AuNFs, the biomolecules adsorbed onto the surface of the nanoparticles should have different characteristics, such as conformation, molecular weight, and isoelectric point (pI). Proteins with a different pI carry different charges in a given solution that will influence the electrostatic interactions with the surface of the particles [71,72]. Regarding the HD variation, all the AuNPs showed an increase in HD values after being in contact with saliva and urine samples.…”

“…This interaction often referred to as adsorption, can be attributed to electrostatic interactions, hydrophobic interactions, van der Waals' forces, solvation forces, and hydrogen bonding [79]. Some studies revealed the affinity of lysine, arginine, serine, and threonine for citrate ions on the surface of AuNPs [71,82]. It was also found that the first proteins adsorbed on the surface of AuNPs are present in high concentrations and have high association rate constants.…”

Nano-functionalization and evaluation of antimicrobial activity of Tinospora cordifolia against the TolB protein of Pseudomonas aeruginosa – An antibacterial and computational study

“…Thus this phytochemical can shed light on how it binds with different target proteins, aiding researchers in understanding the fundamental mode of action of the drug candidate. Ag and Au nanoparticles are also reported to bind to many proteins, such as serum albumin, hemoglobin, lysozyme, etc., showing good binding affinities ( Sen et al, 2011 ; Aich et al, 2020 ; Shahabadi et al, 2023 ).…”

A comparative study on the interaction of gold nanoparticles with trypsin and pepsin: thermodynamic perspectives

“…8 The interaction between AuNPs and plasma proteins had been paid significant attention in recent years, such as serum albumin, 3,[8][9][10][11][12][13][14] g-globulin, 8,15 hemoglobin, 16,17 fibrinogen, 8,18 transferrin, 19 histones and insulin. 8 The interaction of AuNPs with lysozyme, 9,[20][21][22][23] papain, 24 yeast alcohol dehydrogenase, 25 a-amylase, 26 cholesterol oxidase enzyme 27 a-thrombin, 28 and chymotrypsin 29 has also been studied. Conversely, much less is known about the interaction of AuNPs with proteins from the digestive system.…”